Managed to make a tool to press them out, they were completely knackered, they have clearly not been inspected since the car was built. Have replaced with some forward shooting 45 jets from Eurocarb. one of the pump jet circuits was so blocked I needed to remove the lead plug and drill it out, even a high pressure line didn't shift it. 40 years of gunk that had turned in to something resembling granite. Rest of the carbs had the usual accumulation in the pump housing and varnish everywhere.
Cleaned and refurbished the carbs and reassembled- put them back on car this morning, fired up first time after a 3 month lay off! (I haven't even balanced or set the mixtures yet)- leapt into life.
Sounds like a different engine, well pleased.